NGC3372 Carina nebula in RGB

[sgazer]

hi, following on from my previous post of NGC3372 in Ha http://stargazerslounge.com/imaging-deep-sky/147187-ngc3372-carina-nebula.html

I've now managed to construct an RGB image from the Ha data and OIII data, this is my first real attempt at this.

I used the CFA split command in Iris to extract the red and green channels from the raw files before the bayer matrix was combined (this avoiding adding the noise from the blue pixels). This works especially well for green (OIII) as there are twice as many green pixels as red (Ha), or blue. I had to do the same for the darks. I then used DSS to stack the resulting FITs, using a Ha frame as the reference when the OIII was stacked, so DSS aligned the OIII to the Ha to make it easier to layer the channels in Photoshop. Then used PS actions to generate a green channel from the red and blue (OIII). I also have a lum stack, but have not added it yet as it doesn't seem to have any more detail than the RGB. No noise reduction on this, no flats. Ha=36x3min ISO 800. OIII=30 (from 15 subs)x3min ISO800.

I've added a copy of the Lum as well as a comparison to see if it was worth the effort to get the RGB image. I think there is more detail in there, but the UHC filter seems to do a pretty good job for the Lum too.

Thanks for looking.

[Doug]

Hi

I think this is a fantastic image, well done love the colours

Doug

Essex

[sgazer]

Thanks Doug.

And here it is with a little local contract enhancement, thanks to a comment I read from Olly about another image.

[Tom OD]

Lovely shot, I'm not familar with Iris s/w but its working very well for you.

Tom

[whirlpool5194]

Super image, such a shame its soooo far south!!

Wp

[mark7331]

Amazing image. I absolutely love the colours! Nice one

[twotter]

Very nice - has some real depth to it, almost 3D to my eyes

[MikeD]

Fantastic result, congrats.

Sooo much going on, I wish I could have a go at this.

Mike.

[mike_777]

good depth!

[sgazer]

Thanks all for your comments.

I've been doing a few tests to see if running the raw files through Iris to split the channels before they are debayered makes a different to the noise level (contributed by the unwanted channels) and I can't really see a difference, although I've read that it does. But it doesn't really seem worth the effort, as it's a completely manual command line operation on each image, including darks, to do it in Iris.